Poly (trimethylene furandicarboxylate (PTF) is a renewable polyester and can be synthesized via the polycondensation reaction of 2,5-furandicarboxylic acid or 2,5-furandicarboxylic acid diester with 1,3-propane diol. Compared with polyethylene terephthalate (PET), PTF demonstrates improved oxygen and carbon dioxide barrier properties that are very important for the carbonated beverage and food packaging industry.
The quality of the 2,5-furandicarboxylic acid diester, especially the color of the monomer is important for obtaining the high quality, colorless PTF that is required for the beverage, food and packaging industries. The process for producing 2,5-furandicarboxylic acid and its diesters in a renewable manner proceeds via the oxidation of hydroxymethyl furfural (HMF). HMF from renewable resources is often contaminated with highly colored polymeric impurities called humins. The removal of humins from processes producing furandicarboxylic acid and its diesters continues to be a problem.
The present disclosure relates to efficient processes for producing both furan dicarboxylic acid and its diesters that are substantially free from humins, from hydroxymethyl furfural contaminated with humins.